Backing up MongoDB Databases in Dokku Containers to Dropbox

I’ve recently moved my Slack bots to Dokku running on DigitalOcean. The bots use local MongoDB database containers provided by the dokku-mongo plugin. Here’s the entire setup, from installation to backup to Dropbox.

Install

dokku plugin:install https://github.com/dokku/dokku-mongo.git mongo

Create a Database

This starts a MongoDB instance which is not accessible from the outside world.

root@dblock-plum:/# dokku mongo:create market-bot
-----> Starting container
       Waiting for container to be ready
=====> MongoDB container created: market-bot
       DSN: mongodb://market-bot:******@dokku-mongo-market-bot:27017/market-bot

Backup with Dropbox

You can certainly rely on DigitalOcean’s weekly system backup or any other backup system. However I wanted a daily backup and a historical archive of the data in each individual MongoDB. I also wanted it to be free or cheap.

Install Dropbox

cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86_64" | tar xzf -

This creates ~/.dropbox-dist, and you can manually start Dropbox via ~/.dropbox-dist/dropboxd.

Configure First Time

Run Dropbox for the first time.

~/.dropbox-dist/dropboxd

Dropboxd will tell you “This client is not linked to any account …“ and give you a link copy that and paste it in your local web browser, authenticate and validate the new connection. You can stop the daemon with Ctrl+C.

Auto-Start

Create /etc/init.d/dropbox from this gist, eg. sudo vi /etc/init.d/dropbox. Edit DROPBOX_USERS below (eg. user1 user2). I just use root.

DROPBOX_USERS="root"

DAEMON=.dropbox-dist/dropboxd

...

Set it to automatically start on boot.

sudo chmod +x /etc/init.d/dropbox
sudo update-rc.d dropbox defaults

Start the service.

service dropbox start

Check that it’s running.

service dropbox status
dropboxd for USER root: running (pid 993)

Selective Sync

If you need selective sync, check out this blog post.

Backup MongoDB Databases

Create an Export Script

Create Dropbox/bin/dokku-mongo-export.sh. It enumerates Dokku MongoDB databases and runs mongo:export on them. The archive that mongo:export produces is gzipped archive output of mongodump.

Notice I just put the script in my Dropbox ;)

#!/bin/bash

echo "Backing up MongoDB databases to Dropbox ..."

dt=$(date +"%Y-%m-%d")

echo " today is $dt"

BACKUP_PATH=~/Dropbox/mongo/backup/$(date +"%Y")/$(date +"%B")
echo " creating $BACKUP_PATH .."

dbs=$(dokku mongo:list | grep -v ===)

for db in $dbs
do
  echo " backing up $db ..."
  mkdir -p $BACKUP_PATH/$db
  f=$BACKUP_PATH/$db/$dt-$db.dump.gz
  dokku mongo:export $db > $f
done

The latest version of this script is here as a gist. Make sure to chmod 700 dokku-mongo-export.sh and run it manually to test.

Run the Script Daily

cd /etc/cron.daily/
ln -s /root/Dropbox/bin/dokku-mongo-export.sh dokku-mongo-export

Note that only executables without an extension run from /etc.cron.*/, hence the name of the symbolic link is different from the script.

Restoring Data

The archive that mongo:export produces is gzipped archive output of mongodump. To restore in Dokku, use mongo:import. To restore locally, run mongorestore --gzip --archive=filename.

Neat

This will neatly organize your database backups in Dropbox.

backups

Daniel Doubrovkine

Backing up MongoDB Databases in Dokku Containers to Dropbox mongodb